[Kenwood] Kenwood TS-940SAT S Meter

Thu Feb 5 10:28:10 EST 2015

It's labeled RB and in the first set of instructions for alignment.

Might I suggest you not adjust anything, it's working. A lot of the
adjustments require test equipment beyond most home shops. Some of the
adjustments seem benign enough like the AGC voltage setting. But when you
adjust the AGC voltage you have to recalibrate the S-Meter. The service
manual expects you to start on Pg 1 and go thru every step in order. A lot
of steps affect steps on down the page so you can't jump around. If you
want to go thru and take notes on the different readings in each step
without adjusting anything that's OK.

First Rule: "If it ain't broke, don't fix it"

On Wed, Feb 4, 2015 at 10:50 PM, Brian Tempero <btempero at stanford.edu>
wrote:

> Clif,
>
> Thank you for the information. I did the “internal Calibrator” test per
> your instructions and it read S9. May I ask another question? On page 50 of
> the users guide. Section 11-2 adjustments 1 and 2. Where do I put the leads
> of my volt meter to test the voltage? I looked in the service manual and it
> was still vague.
>
> Thank you very much for your help. I really appreciate it.
>
> Brian Tempero
> HIVE Manager
> 650-724-8122
>
>
> From: Clif <clif at avvid.com>
> Date: Wednesday, February 4, 2015 at 9:27 AM
> To: MarioDaniele Greco <daniele_mdg at yahoo.it>
> Cc: ICME <btempero at stanford.edu>, "kenwood at mailman.qth.net" <
> kenwood at mailman.qth.net>
> Subject: Re: [Kenwood] Kenwood TS-940SAT S Meter
>
> Easiest way to check is turn on the internal calibrator. It is after the
> attenuator relays and leaves them out as a problem. It should read S7-9 on
> a properly aligned radio on 20m @ 14.2 in USB. If that is correct and an on
> air signal is way low then the attenuator relays need to be replaced. If
> it's not S-7-9 a signal calibrated output generator is needed to determine
> if the problem is s-meter setting or the rx sensitivity is actually down
> due to a problem.
>
> As a note the 940's were aligned to the Collins spec, 50uv = S-9, FWIW S-1
> = 1.25uv. The levels in the service manual are different because the SG
> output is speced into an open load not 50 ohm.
>
> On Wed, Feb 4, 2015 at 11:06 AM, MarioDaniele Greco <daniele_mdg at yahoo.it>
> wrote:
>
>> Hi,
>> same "problem" here with my TS-940, one of the latest serial numbers, 9
>> Millionxxx. My S-meter moves only when signals are stronger than S5-S6.Some
>> typical TS-940  issues are :- S-meter scale is calibrated according to
>> Japanese scale, where S1 japanese = S5 in the  Collins USA signal scale.-
>> there is a PIN diode attenuator, in RF board,  exactly after the RX input
>> filters, before the RF cascode FET amplifier,  that could be out of
>> calibration: the reference value is adjusted by VR1 in RF board. See
>> service manual for the right values
>> - the input attenuator relays could have dirty contacts
>> Last, but not least, if your radio is very old, it could be necessary to
>> check the whole RF-IF signal chain. The Service Manual is of help.
>> Just try this : switch to lower band, 500KHz - 1.5 MHz: if  the received
>> signals or noise level is strong, and the S-meter goes to S6 or beyond,
>> this means that the at least the signal chain is OK, otherwise it needs to
>> be services.Hope this helpes73MarioIZ0IRH
>>      Da: brian tempero <btempero at stanford.edu>
>>  A: kenwood at mailman.qth.net
>>  Inviato: Martedì 3 Febbraio 2015 18:19
>>  Oggetto: [Kenwood] Kenwood TS-940SAT S Meter
>>
>> All,
>>
>> This is my first post. I have a strange issue with my kenwood ts-940SAT.
>> Here is the issue:
>> My radio receives and transmits very well. The issue is that my S meter
>> barely works. If a really strong signal comes in the needle spikes and
>> then
>> slowly descends. If the signal is not really strong the needle does not
>> move.
>> When I transmit the needle works without issue in all settings (power,
>> swr,
>> acl and so on).  I have all the knobs set per the operating manual for
>> first
>> use. I am stumped at this issue.
>>
>> Thank you for reading this issue and all comments or suggestions are
>> welcome.
>>
>> Brian Tempero
>> HIVE Manager
>> Stanford University
>> 650-724-8122
>>
>>
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>
>
>
> --
> Clif Holland KA5IPF
> www.avvid.com
>

-- 
Clif Holland KA5IPF
www.avvid.com